This invention relates to fire prevention sprinklers for distributing a fire extinguishing liquid such as water in an environment which is subject to a fire hazard.
Many conventional fire prevention sprinklers consist of a threaded sprinkler body connected to a water supply pipe to receive water under pressure and having a heat-responsive arrangement blocking a passage in the sprinkler body which is set to open the passage when the temperature in the vicinity of the sprinkler exceeds a selected value. In order to distribute the water emerging from the sprinkler passage throughout the area to be protected, the sprinkler includes a deflector which is supported from the sprinkler body by arms so that water emerging from the sprinkler passage upon activation of the sprinkler impinges the deflector and is distributed thereby over the area to be protected.
Concealed sprinklers are usually covered by a cover plate which is substantially flush with a ceiling in which the sprinkler is mounted and have a deflector supported from the sprinkler body by sliding pins rather than fixed arms, permitting the deflector to be held in a retracted position above the ceiling and adjacent to the sprinkler body and to drop down to an extended position below the surface of the ceiling automatically and concurrently with the operation of the sprinkler after the cover has been released by a high temperature condition. For light hazard occupancies a quick response sprinkler having an 11 K factor should be able to distribute water substantially uniformly over areas of 16'.times.16' or 18'.times.18' for quick response and 20'.times.20' for standard response, but uniform distribution patterns for concealed extended coverage sprinkler have been difficult to achieve over such areas with conventional deflector arrangements.
The Leininger et al. U.S. Pat. No. 4,880,063 discloses an adjustable concealed sprinkler having a circular drop-down deflector supported by sliding pins and provided with an array of peripheral slots. The Meyer et al. U.S. Pat. No. 5,664,630 discloses a concealed extended coverage sprinkler arrangement having a drop-down deflector consisting of a planar deflector plate having radial slots and a central protrusion extending axially toward the sprinkler passage and supported by sliding pins from the sprinkler body. The Galaszewski U.S. Pat. No. 5,372,203 also discloses a drop-down concealed sprinkler having a deflector with radial slots supported by sliding pins from the sprinkler body. The Fischer et al. U.S. Pat. No. 5,152,344 and the Polan U.S. Pat. No. 5,083,616 disclose similar arrangements.